The invention relates as indicated to a guard ring for a flush-type lawn sprinkler head. Lawn sprinkling systems including an underground piping layout and a plurality of spaced lawn sprinkling heads are well known. Experience has shown that protection of the sprinkling heads from lawnmowers, and particularly rotary lawnmowers is necessary. A commonly employed guard ring is a cast concrete "doughnut" which serves as a protective collar. This requires the ground to be cut away around the sprinkler head to provide a recess for the doughnut so that the cap of the doughnut is close to ground level to permit lawnmower wheels etc. to roll over the doughnut. To overcome a tipping problem with the concrete doughnut protector, often times the upstanding pipe leading to the sprinkler head is surrounded with a concrete sleeve which rests well into the ground or on the horizontal pipe. This collar provided a base on which the concrete doughnut is seated without holddown means. In the absence of such a base, there is a tendency for the doughnut to tip as a lawnmower wheel passes thereover causing the trailing edge thereof to raise up and engage the reel or the rotor blades of the lawnmower with resulting damage to both. This problem is particularly evident in loose sandy soils such as are found in Florida.
U.S. Pat. No. 3,662,956 shows one form of sprinkler protector formed of concrete and having frustoconical sidewalls extending below ground level to the level of the underground feeder pipe. In order to prevent damage due to impact, as by a lawnmower wheel on the top of the sprinkler head, an underlying circumferential shoulder is provided in the protector to support the underside of the sprinkler head. Still other devices are known which are integral with the piping system for protecting a sprinkler head, such a pop-up type sprinkler head as shown in the patent to Trickey U.S. Pat. No. 3,404,840.
The present invention as compared to concrete doughnuts more readily accommodates and protects sprinkler heads which, after installation and perhaps after the sodding of the surrounding ground, or because of settling ground after installation, project somewhat above the ground level rather than being flush therewith. The flared skirt provides a ramp for the lawnmower and enables the wheel to more readily ride over a guard ring and thus minimizes the wheel obstruction and tipping or dislodging problems in using a guard ring to protect a sprinkler head which is somewhat above the level of the surrounding ground. Obviously, neither the guard ring or sprinkler head can be high enough to interfere with the passage of the reel or blade of a lawnmower over the ring and head.
The guard ring is preferably made of filled or unfilled plastic or similar material, e.g., pigmented polyethylene or pigmented polypropylene so that in the event one is tipped into or otherwise hits the blade or reel of a mower, little or no damage results to the mower.
The present invention provides a low cost guard ring which can be easily installed and is self-positioning with respect to ground level and which is constructed so that the guard ring may project a greater distance above the ground level than the conventional concrete doughnut and yet without creating an objectionable obstruction to lawn mower wheels and the like.